1. Field of the Invention
The present invention relates to an image forming apparatus, a program product, and a storage medium storing the program product for electronic sort printing all pages of an original at once or by plural portions, even when the total data size of the original exceeds the available space in a memory.
2. Description of the Related Art
An important function of image forming apparatuses equipped with a scanner function, such as PPCs (Plain Paper Copiers), is to scan an original document and perform electronic sort printing.
To perform electronic sort printing, the original is scanned by the scanner function, and image data obtained by scanning the original need to be loaded (hereinafter referred to as “stored”) in a storage device such as a memory. However, the storage device provided in the image forming apparatus may not always be capable of storing the image data corresponding to all pages of the original.
This is because the size of the image data obtained is significantly affected by scanning conditions when scanning the original (conditions such as paper size, color mode, and resolution). Further, the available space in the storage device is significantly affected by the operational status of the image forming apparatus.
Therefore, even when all pages of an original are scanned, the image forming apparatus may not be able to print them out.
To address this problem, several methods have been proposed. When it is determined that electronic sort printing cannot be performed, the image data obtained are compressed or converted from multiple-valued data to binary data. Another method is to detect the width of the scanned original, calculate the data size of all pages of the original based on the detected width, and to secure a space in the storage device corresponding to the calculated data size (see, for example, Patent Documents 1 and 2).
Patent Document 1: Japanese Laid-Open Patent Application No. H5-37747
Patent Document 2: Japanese Laid-Open Patent Application No. H7-307848
With the method disclosed in Patent Document 1, the number of pages to be electronic sort printed can be increased. However, there still remains the possibility that the storage device cannot store data corresponding to all pages of the original. Accordingly, the user's request might not be fulfilled. Moreover, when the image data are converted from multiple-valued data to binary data, printing quality is degraded.
In the method disclosed in Patent Document 2, it may not be possible to secure space in the storage device large enough to store the image data. Accordingly, the user's request might not be fulfilled.